U.S. Pat. No. 3,231,223 is a flight attitude control system having six thrusters which can change a flying body's spin rate and change the orientation of its spin axis with respect to its pitch and yaw axes; however, the system is not capable of adding translational velocity along the pitch or yaw axes without changing the orientation of the spin axis; translational forces are in fact intentionally avoided, col. 1, lines 38-55. The patent refers to the prior art as teaching that twelve thrusters are required to perform the three functions that are performed by the present invention with as few as four thrusters; col. 1, lines 21-23. Addition of velocity in the patented system entails excessive torque, because the thruster axes do not pass through the center of mass of the flying body. Moving the thruster axes through the center of mass would cause other problems.
U.S. Pat. No. 3,907,226 shows a four thruster control scheme for spin stabilized devices. Although the patented scheme performs the present invention's functions of reorienting the spin axis and adding velocity along the negative spin axis, it does not perform the remaining functions of adding velocity in other directions or changing the spin rate. If these functions were performed, at least three additional thrusters would be required.
U.S. Pat. No. 4,288,051 discloses a method and apparatus for controlling a satellite about three orthogonal axes, not for controlling a spinning projectile. The patent shows fourteen jet nozzles 14.
U.S. Pat. No. 3,429,526 discloses an apparatus for tilting the orbital plane of a non-spinning space vehicle using five jets and a gravity boom pointing away from the earth.
Secondary references are: U.S. Pat. Nos. 2,974,594; 3,189,299; 3,612,442; 3,643,897; 3,802,190; 3,866,025; 3,977,633; and 4,407,469.